Nowadays, an ultrahigh resolution and high pixel density (PPI) technology is employed to achieve a vivid display effect. 300 PPI is a maximum resolution that can be identified by human eyes. If the pixel density of a display device exceeds 300 PPI, human eyes would not distinguish individual pixels and no longer have granular sensation, so that the display device with such resolution is close to a paper product for human eyes. Since the resolution has gone beyond the maximum resolution that can be identified by human eyes, the high PPI technology is also called as a retina display technology. However, high PPI technology presents a challenge to pixel design, and it is required to ensure the overall display effect of the display device while maintaining the transmittance of each pixel. The uniformity of a common electrode signal of the display device has a significant influence on the flicker and crosstalk and so on. The larger the display device is, the greater effect of the stability of the common electrode signal on the overall display effect is.
In a conventional array substrate, each pixel unit only comprises one Thin-Film Transistor (TFT), and an Integrated Circuit (IC) only provides one common electrode voltage. As shown in FIG. 1, at the moments of turning on and off the data line signal voltage (curve A), the common electrode voltage (curve B) fluctuates due to the influence of the data line signal voltage (the circled area in FIG. 1). That is, the common electrode voltage is increased or decreased by about 0.5V by the data line signal voltage. Unstable common electrode voltage will result in the flicker of the display device.